Microbicidal composition

ABSTRACT

An aqueous microbicidal composition having two components. The first component is a nonionic surfactant with structure: R 2 O(CH 2 CH(CH 3 )O) 3 (CH 2 CH 2 O) 5 H, where R 2  is a mixture of C 8 -C 14  linear alkyl groups. The second component is a benzoate or sorbate salt. The weight ratio of the nonionic surfactant to the benzoate or sorbate salt is from 1:0.12 to 1:109.7646.

This invention relates to microbicidal compositions containing benzoateor sorbate and a surfactant.

A composition containing 5-chloro-2-methylisothiazolin-3-one,2-methylisothiazolin-3-one and a nonionic dispersant is disclosed inU.S. Pat. No. 4,295,932. The composition contains a 3:1 mixture of5-chloro-2-methylisothiazolin-3-one and 2-methylisothiazolin-3-one, anda copolymer of ethylene oxide and propylene oxide which appears to havethe same composition as PLURONIC L61 or TERGITOL L61 dispersant.However, there is a need for combinations of microbicides havingsynergistic activity against various strains of microorganisms toprovide effective control of the microorganisms. Moreover, there is aneed for such combinations containing lower levels of individualmicrobicides for environmental and economic benefit. The problemaddressed by this invention is to provide such synergistic combinationsof microbicides.

STATEMENT OF THE INVENTION

The present invention is directed to a synergistic microbicidalcomposition comprising: (a) a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups; and (b) a benzoateor sorbate salt; wherein a weight ratio of said nonionic surfactant tothe benzoate or sorbate salt is from 1:0.12 to 1:109.7646.

The present invention is further directed to a synergistic microbicidalcomposition comprising: (a) a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups; and (b) a benzoateor sorbate salt; wherein a weight ratio of said nonionic surfactant tothe benzoate salt is from 1:3.6010 to 1:109.7646 and a ratio of saidnonionic surfactant to the sorbate salt is from 1:0.06 to 1:0.5714 or1:2.3990 to 1:109.7646.

The present invention is further directed to a synergistic microbicidalcomposition comprising: (a) a nonionic surfactant with structure:R¹O(CH₂CH(CH₃)O)₅(CH₂CH₂O)₉Hwhere R¹ is a C₈ alkyl group; and (b) a sorbate salt; wherein a weightratio of said nonionic surfactant to the sorbate salt is from 1:0.1 to1:0.9143.

The present invention is further directed to methods for inhibiting thegrowth of microorganisms in aqueous media by adding to an aqueous mediuma nonionic surfactant as described herein and a benzoate or sorbate saltin the ratios described herein.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the following terms have the designated definitions,unless the context clearly indicates otherwise. The term “microbicide”refers to a compound capable of inhibiting the growth of or controllingthe growth of microorganisms; microbicides include bactericides,fungicides and algaecides. The term “microorganism” includes, forexample, fungi (such as yeast and mold), bacteria and algae. Thefollowing abbreviations are used throughout the specification: ppm=partsper million by weight (weight/weight), mL=milliliter. Unless otherwisespecified, temperatures are in degrees centigrade (° C.), references topercentages are percentages by weight (wt %) and amounts and ratios areon an active ingredient basis, i.e., total weight of benzoate or sorbatesalt and the nonionic surfactant. Numbers of polymerized units ofpropylene oxide or ethylene oxide are number averages.

Preferably, the benzoate or sorbate salt is an alkali metal salt;preferably lithium, sodium or potassium; preferably sodium or potassium.Preferably, the benzoate salt is sodium benzoate. Preferably, thesorbate salt is potassium sorbate. The term “benzoate or sorbate salt”encompasses mixtures of benzoate and sorbate salts.

Preferably, the weight ratio of the nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups to the benzoate saltis from 1:0.5 to 1:100. Preferably, the weight ratio of the nonionicsurfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups to the sorbate saltis from 1:1 to 1:100. Preferably, the weight ratio of the nonionicsurfactant with structure:

R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇H where R² is a mixture of C₈-C₁₄ linearalkyl groups to the sorbate salt is from 1:5 to 1:100.

The present invention is further directed to a method for inhibiting thegrowth of S. aureus in an aqueous medium by adding: (a) a nonionicsurfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups; and (b) a benzoateor sorbate salt; wherein a weight ratio of said nonionic surfactant tothe benzoate or sorbate salt is from 1:2.9982 to 1:109.7646.

The present invention is further directed to a method for inhibiting thegrowth of mold, preferably A. niger, in an aqueous medium by adding: (a)a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups; and (b) a benzoateor sorbate salt; wherein a weight ratio of said nonionic surfactant tothe benzoate or sorbate salt is from 1:0.12 to 1:13.7143.

The present invention is further directed to a method for inhibiting thegrowth of S. aureus in an aqueous medium by adding: (a) a nonionicsurfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups; and (b) a benzoatesalt; wherein a weight ratio of said nonionic surfactant to the benzoatesalt is from 1:3.6010 to 1:109.7646; preferably from 1:10.2886 to1:109.7646.

The present invention is further directed to a method for inhibiting thegrowth of S. aureus in an aqueous medium by adding: (a) a nonionicsurfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups; and (b) a sorbatesalt; wherein a weight ratio of said nonionic surfactant to the sorbatesalt is from 1:2.3990 to 1:109.7646.

The present invention is further directed to a method for inhibiting thegrowth of mold, preferably A. niger, in an aqueous medium by adding: (a)a nonionic surfactant with structure:R¹O(CH₂CH(CH₃)O)₅(CH₂CH₂O)₉Hwhere R¹ is a C₈ alkyl group; and (b) a sorbate salt; wherein a weightratio of said nonionic surfactant to the sorbate salt is from 1:0.1 to1:0.9143; preferably from 1:0.1 to 1:0.2857 or 1:0.3429 to 1:0.9143.

The present invention is further directed to an aqueous compositioncomprising from 5 to 40 wt % of a benzoate or sorbate salt and anonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅Hwhere R² is a mixture of C₈-C₁₄ linear alkyl groups, wherein a weightratio of said nonionic surfactant to the benzoate or sorbate salt isfrom 1:0.5 to 1:100. In one preferred embodiment, the benzoate orsorbate salt is a benzoate salt and the weight ratio is from 1:0.5 to1:100. In another preferred embodiment, the benzoate or sorbate salt isa sorbate salt and the weight ratio is from 1:1 to 1:100. Preferably thecomposition comprises from 5 to 35 wt % of a benzoate or sorbate salt,preferably from 10 to 30 wt %. Preferably, the composition comprisesfrom 20 to 90 wt % water, preferably from 30 to 80 wt %.

The present invention is further directed to an aqueous compositioncomprising from 25 to 40 wt % of a sorbate salt and a nonionicsurfactant with structure: R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇H where R² is amixture of C₈-C₁₄ linear alkyl groups, wherein a weight ratio of saidnonionic surfactant to the sorbate salt is from 1:5 to 1:100. Preferablythe composition comprises from 28 to 38 wt % of a sorbate salt,preferably from 30 to 35 wt %. Preferably, the composition comprisesfrom 50 to 75 wt % water, preferably from 55 to 72 wt %.

R² is a mixture of C₈-C₁₄ linear alkyl groups. Preferably, the C₈-C₁₄linear alkyl groups comprise from 50 to 85 wt % C₈-C₁₀ linear alkylgroups and 15 to 50 wt % C₁₂-C₁₄ linear alkyl groups, preferably from 60to 75 wt % C₈-C₁₀ linear alkyl groups and 25 to 40 wt % C₁₂-C₁₄ linearalkyl groups, preferably about 70 wt % C₈-C₁₀ linear alkyl groups andabout 30 wt % C₁₂-C₁₄ linear alkyl groups. Preferably, the linear alkylgroups are derived from seed oil.

Preferably, each of the synergistic microbicidal compositions issubstantially free of microbicides other than the nonionic surfactantand the sorbate or benzoate salt, i.e., it has less than 1 wt % ofmicrobicides other than the nonionic surfactant and the sorbate orbenzoate salt based on total weight of active ingredients, preferablyless than 0.5 wt %, preferably less than 0.2 wt %, preferably less than0.1 wt %. Preferably, when the nonionic surfactant and the sorbate orbenzoate salt are added to an aqueous medium, the medium issubstantially free of other microbicides, i.e., it has less than 1 wt %of microbicides other than the nonionic surfactant and the sorbate orbenzoate salt based on total weight of active ingredients, preferablyless than 0.5 wt %, preferably less than 0.2 wt %, preferably less than0.1 wt %.

The compositions of this invention may contain other ingredients, e.g.,defoamers and emulsifiers. The microbicidal compositions of the presentinvention can be used to inhibit the growth of microorganisms or higherforms of aquatic life (such as protozoans, invertebrates, bryozoans,dinoflagellates, crustaceans, mollusks, etc) by introducing amicrobicidally effective amount of the compositions into an aqueousmedium subject to microbial attack. Suitable aqueous media are found in,for example: industrial process water; electrocoat deposition systems;cooling towers; air washers; gas scrubbers; mineral slurries; wastewatertreatment; ornamental fountains; reverse osmosis filtration;ultrafiltration; ballast water; evaporative condensers; heat exchangers;pulp and paper processing fluids and additives; starch; plastics;emulsions; dispersions; paints; latices; coatings, such as varnishes;construction products, such as mastics, caulks, and sealants;construction adhesives, such as ceramic adhesives, carpet backingadhesives, and laminating adhesives; industrial or consumer adhesives;photographic chemicals; printing fluids; household products, such asbathroom and kitchen cleaners; cosmetics; toiletries; shampoos; soaps;personal care products such as wipes, lotions, sunscreen, conditioners,creams, and other leave-on applications; detergents; industrialcleaners; floor polishes; laundry rinse water; metalworking fluids;conveyor lubricants; hydraulic fluids; leather and leather products;textiles; textile products; wood and wood products, such as plywood,chipboard, flakeboard, laminated beams, oriented strandboard, hardboard,and particleboard; petroleum processing fluids; fuel; oilfield fluids,such as injection water, fracture fluids, and drilling muds; agricultureadjuvant preservation; surfactant preservation; medical devices;diagnostic reagent preservation; food preservation, such as plastic orpaper food wrap; food, beverage, and industrial process pasteurizers;toilet bowls; recreational water; pools; and spas.

The specific amount of the microbicidal compositions of this inventionnecessary to inhibit or control the growth of microorganisms in anapplication will vary. Typically, the amount of the composition of thepresent invention is sufficient to control the growth of microorganismsif it provides from 1,000 to 30,000 ppm (parts per million) activeingredients of the composition. It is preferred that the activeingredients (i.e., nonionic surfactant and sorbate or benzoate salt) ofthe composition be present in the medium to be treated in an amount ofat least 2,000 ppm, preferably at least 3,000 ppm, preferably at least4,000 ppm, preferably at least 6,000 ppm, preferably at least 8,000 ppm.It is preferred that the active ingredients of the composition bepresent in the locus in an amount of no more than 25,000 ppm, preferablyno more than 20,000 ppm, preferably no more than 15,000 ppm, preferablyno more than 10,000 ppm, preferably no more than 8,000 ppm. In a methodof this invention, a composition is treated to inhibit microbial growthby adding, together or separately, the nonionic surfactant and sorbateor benzoate salt, in amounts that would produce the concentrationsindicated above.

EXAMPLES

Surfactants and biocides were evaluated for synergy by determining thesynergy index (S.I.) of the combination. Synergy index was calculatedbased on minimum inhibitory concentrations (MIC) of two antimicrobialcompounds (A and B) alone and in combinations. The tests organisms wereGram negative bacteria (Pseudomonas aeruginosa ATCC #15442), Grampositive bacteria (Staphylococcus aureus ATCC #6538), yeast (Candidaalbicans ATCC#10203) and mold (Aspergillus niger ATCC#16404). Contacttime for the bacteria was 24 and 48 hours, yeast was 48 and 72 hrs, and3 and 7 days for mold. The test was carried out in 96 well microtiterplates.R¹O(CH₂CH(CH₃)O)₅(CH₂CH₂O)₉H,  Surf. Awhere R¹ is 2-ethylhexylR²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅H  Surf. DR²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇H  Surf. EIn Surf. D and Surf. E, R² is a mixture of C₈-C₁₄ linear alkyl groups(70% C₈-C₁₀ linear alkyl and 30% C₁₂-C₁₄ linear alkyl)

Inoculums Used Inoculum Size of organisms (CFU/ml) StaphylococcusPseudomonas Aspergillus Candida aureus aeruginosa niger albicansSurfactants ATCC# 6538 ATCC # 15442 ATCC# 16404 ATCC#10203 Surf. A1.156E+06 8.134E+07 1.156E+06 1.156+06 Surf. D 1.808E+05 1.156E+081.156E+06 5.726E+05 Surf. E 1.808E+06 5.727E+07 5.726E+05 1.808E+06

TABLE 4 Media Used Media Used for testing Staphylococcus PseudomonasAspergillus Candida aureus aeruginosa niger albicans ATCC# 6538 ATCC #15442 ATCC# 16404 ATCC#10203 10% Tryptic 10% Tryptic Potato Potato soybroth soy broth dextrose broth dextrose broth

The pH of the Triptic soy broth was 7.3 and the Potato dextrose brothwas 5.1

The test results for demonstration of synergy of the MIC combinationsare shown in the tables below. Each table shows the results forcombinations of two components against the microorganisms tested withincubation times; the end-point activity in ppm measured by the MIC forcompound A alone (CA), for component B alone (CB), and the mixture (Ca)and (Cb); the calculated SI value; and the range of synergistic ratiosfor each combination tested. SI is calculated as follows:Ca/CA+Cb/CB=Synergy Index (“SI”)

Wherein:

-   -   CA=concentration of compound A in ppm, acting alone, which        produced an end point (MIC of Compound A).    -   Ca=concentration of compound A in ppm, in the mixture, which        produced an end point.    -   CB=concentration of compound B in ppm, acting alone, which        produced an end point (MIC of Compound B).    -   Cb=concentration of compound B in ppm, in the mixture, which        produced an end point.        When the sum of Ca/CA and Cb/CB is greater than one, antagonism        is indicated. When the sum is equal to one, additivity is        indicated, and when less than one, synergism is demonstrated.

The ratio ranges at which sorbate, benzoate and the surfactants weretested are as summarized in the following tables:

Sodium Benzoate with Surf. A Organism ATCC# From To Ratio RangeStaphylococcus 6538 0.2:20,000 1,000:218.75 1:0.00001- aureus 1:4.5714Aspergillus niger 16404 0.2:20,000 1,000:218.75 1:0.00001- 1:4.5714Candida albicans 10203 0.2:20,000 1,000:218.75 1:0.00001- 1:4.5714Pseudomonas 15442 0.2:20,000 1,000:218.75 1:0.00001- aeruginosa 1:4.5714

Sodium Benzoate with Surf. E Organism ATCC# From To Ratio RangeStaphylococcus 6538 6.0:20,000 30,000:218.75 1:0.0003- aureus 1:137.143Aspergillus niger 16404 0.2:20,000  1,000:218.75 1:0.00001- 1:4.5714Candida albicans 10203 0.2:20,000  1,000:218.75 1:0.00001- 1:4.5714Pseudomonas 15442 6.0:20,000 30,000:218.75 1:0.0003- aeruginosa1:137.143

Sodium Benzoate with Surf. D Organism ATCC# From To Ratio RangeStaphylococcus 6538 6.0:20,000 30,000:218.75 1:0.0003- aureus 1:137.143Aspergillus niger 16404 6.0:20,000 30,000:218.75 1:0.0003- 1:137.143Candida albicans 10203 6.0:20,000 30,000:218.75 1:0.0003- 1:137.143Pseudomonas 15442 6.0:20,000 30,000:218.75 1:0.0003- aeruginosa1:137.143

Potassium Sorbate with Surf. A Organism ATCC# From To Ratio RangeStaphylococcus 6538 0.2:20,000 1,000:218.75 1:0.00001- aureus 1:4.5714Aspergillus niger 16404 0.2:20,000 1,000:218.75 1:0.00001- 1:4.5714Candida albicans 10203 0.2:20,000 1,000:218.75 1:0.00001- 1:4.5714Pseudomonas 15442 0.2:20,000 1,000:218.75 1:0.00001- aeruginosa 1:4.5714

Potassium Sorbate with Surf. E Organism ATCC# From To Ratio RangeStaphylococcus 6538 6.0:20,000 30,000:218.75 1:0.0003- aureus 1:137.143Aspergillus niger 16404 0.2:20,000  1,000:218.75 1:0.00001- 1:4.5714Candida albicans 10203 0.2:20,000  1,000:218.75 1:0.00001- 1:4.5714Pseudomonas 15442 6.0:20,000 30,000:218.75 1:0.0003- aeruginosa1:137.143

Potassium Sorbate with Surf. D Organism ATCC# From To Ratio RangeStaphylococcus 6538 6.0:20,000 30,000:218.75 1:0.0003- aureus 1:137.143Aspergillus 16404 6.0:20,000 30,000:218.75 1:0.0003- niger 1:137.143Candida 10203 6.0:20,000 30,000:218.75 1:0.0003- albicans 1:137.143Pseudomonas 15442 6.0:20,000 30,000:218.75 1:0.0003- aeruginosa1:137.143

A: Surf. A B: Sodium Benzoate A. niger ATCC#16404 No Synergy C. albicansATCC#10203 No Synergy Ps. aeruginosa ATCC#15442 No Synergy S. aureusATCC# 6538 No Synergy

A: Surf. D B: Sodium Benzoate Media: PDB Inoculum size: 1.156E+06 PPM AIMIC Values (3rd day) Test Alone Combination Ratio Organism CA CB Ca CbS.I. (Ca:Cb) A. niger 20000 5998 10000 2401 0.90 1:0.2401 ATCC#1640420000 5998 10000 1801 0.80 1:0.1801 20000 5998 10000 1499 0.75 1:0.149920000 5998 10000 1200 0.70 1:0.1200 20000 5998 5000 3000 0.75 1:0.600020000 5998 5000 2401 0.65 1:0.4802 20000 5998 5000 1801 0.55 1:0.360220000 5998 5000 1499 0.50 1:0.2998 20000 5998 5000 1200 0.45 1:0.240020000 5998 2500 3000 0.63 1:1.2000 20000 5998 2500 2401 0.53 1:0.960420000 5998 2500 1801 0.43 1:0.7204 20000 5998 2500 1499 0.37 1:0.599620000 5998 2500 1200 0.33 1:0.4800 20000 5998 1750 3000 0.59 1:1.714320000 5998 1750 2401 0.49 1:1.3720 20000 5998 1750 1801 0.39 1:1.029120000 5998 1750 1499 0.34 1:0.8566 20000 5998 437.5 3000 0.52 1:6.857120000 5998 437.5 2401 0.42 1:5.4880 20000 5998 437.5 1801 0.32 1:4.116620000 5998 437.5 1499 0.27 1:3.4263 20000 5998 218.75 3000 0.511:13.7143 20000 5998 218.75 2401 0.41 1:10.9760 20000 5998 218.75 18010.31 1:8.2331 20000 5998 218.75 1499 0.26 1:6.8526

A: Surf. D B: Sodium Benzoate Media: PDB Inoculum size: 5.726E+05 CFU/mlPPM AI MIC Values (48 hrs) Test Alone Combination Ratio Organism CA CBCa Cb S.I. (Ca:Cb) C. albicans 20000 1200 2500 899 0.87 1:0.3596ATCC#10203 20000 1200 1750 600 0.59 1:0.3429 20000 1200 1750 899 0.841:0.5137

A: Surf. D B: Sodium Benzoate Ps. aeruginosa ATCC#15442 No Synergy

A: Surf. D B: Sodium Benzoate Media: 1/10 TSB Inoculum size: 1.808E+05PPM AI MIC Values (24 hrs) Test Alone Combination Ratio Organism CA CBCa Cb S.I. (Ca:Cb) S. aureus 20000 30000 5000 14991 0.75 1:2.9982 ATCC#20000 30000 1750 14991 0.59 1:8.5663 6538 20000 30000 1750 24011 0.891:13.7206 20000 30000 1750 18005 0.69 1:10.2886 20000 30000 875 240110.84 1:27.4411 20000 30000 875 18005 0.64 1:20.5771 20000 30000 87514991 0.54 1:17.1326 20000 30000 437.5 24011 0.82 1:54.8823 20000 30000437.5 18005 0.62 1:41.1543 20000 30000 437.5 14991 0.52 1:34.2651 2000030000 218.75 24011 0.81 1:109.7646 20000 30000 218.75 18005 0.611:82.3086 20000 30000 218.75 14991 0.51 1:68.5303

A: Surf. E B: Sodium Benzoate A. niger ATCC#16404 No Synergy C. albicansATCC#10203 No Synergy

A: Surf. E B: Sodium Benzoate Media: 1/10TSB Inoculum size: 5.727E+07CFU/ml PPM AI MIC Values (48 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) Ps. aeruginosa 20000 14991 437.5 11995 0.821:27.4171 ATCC#15442 20000 14991 218.75 11995 0.81 1:54.8343

A: Surf. E B: Sodium benzoate Media: 1/10TSB Inoculum size: 1.808E+06CFU/ml PPM AI MIC Values (24 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) S. aureus 20000 30000 5000 18005 0.85 1:3.6010ATCC# 20000 30000 2500 24011 0.93 1:9.6044 6538 20000 30000 1750 240110.89 1:13.7206 20000 30000 1750 18005 0.69 1:10.2886 20000 30000 87524011 0.84 1:27.4411 20000 30000 437.5 24011 0.82 1:54.8823 20000 30000437.5 18005 0.62 1:41.1543 20000 30000 218.75 24011 0.81 1:109.7646

A: Surf. A B: Potassium Sorbate Media: PDB Inoculum size: 1.156E+06CFU/ml PPM AI MIC Values (3rd day) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) A. niger 20000 1000 5000 500 0.75 1:0.1000ATCC#16404 20000 1000 5000 600 0.85 1:0.1200 20000 1000 2500 500 0.631:0.2000 20000 1000 2500 600 0.73 1:0.2400 20000 1000 2500 800 0.931:0.3200 20000 1000 1750 500 0.59 1:0.2857 20000 1000 1750 600 0.691:0.3429 20000 1000 1750 800 0.89 1:0.4571 20000 1000 875 500 0.541:0.5714 20000 1000 875 600 0.64 1:0.6857 20000 1000 875 800 0.841:0.9143

A: Surf. A B: Potassium Sorbate Media: PDB Inoculum size: 1.156E+06CFU/ml PPM AI MIC Values (48 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) C. albicans 20000 800 218.75 600 0.76 1:2.7429ATCC#10203

A: Surf. A B: Potassium Sorbate Ps. aeruginosa ATCC#15442 No Synergy S.aureus ATCC# 6538 No Synergy

A: Surf. D B: Potassium Sorbate Media: PDB Inoculum size: 1.156E+06 PPMAI MIC Values (3rd day) Test Alone Combination Ratio Organism CA CB CaCb S.I. (Ca:Cb) A. niger 20000 5998 10000 2401 0.90 1:0.2401 ATCC#1640420000 5998 10000 1801 0.80 1:0.1801 20000 5998 10000 1499 0.75 1:0.149920000 5998 10000 1200 0.70 1:0.1200 20000 5998 5000 3000 0.75 1:0.600020000 5998 5000 2401 0.65 1:0.4802 20000 5998 5000 1801 0.55 1:0.360220000 5998 5000 1499 0.50 1:0.2998 20000 5998 5000 1200 0.45 1:0.240020000 5998 2500 3000 0.63 1:1.2000 20000 5998 2500 2401 0.53 1:0.960420000 5998 2500 1801 0.43 1:0.7204 20000 5998 2500 1499 0.37 1:0.599620000 5998 2500 1200 0.33 1:0.4800 20000 5998 1750 3000 0.59 1:1.714320000 5998 1750 2401 0.49 1:1.3720 20000 5998 1750 1801 0.39 1:1.029120000 5998 1750 1499 0.34 1:0.8566 20000 5998 437.5 3000 0.52 1:6.857120000 5998 437.5 2401 0.42 1:5.4880 20000 5998 437.5 1801 0.32 1:4.116620000 5998 437.5 1499 0.27 1:3.4263 20000 5998 218.75 3000 0.511:13.7143 20000 5998 218.75 2401 0.41 1:10.9760 20000 5998 218.75 18010.31 1:8.2331 20000 5998 218.75 1499 0.26 1:6.8526

A: Surf. D B: Potassium Sorbate Media: PDB Inoculum size: 5.726E+05CFU/ml PPM AI MIC Values (48 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) C. albicans 20000 1200 2500 899 0.87 1:0.3596ATCC#10203 20000 1200 1750 600 0.59 1:0.3429 20000 1200 1750 899 0.841:0.5137

A: Surf. D B: Potassium Sorbate Ps. aeruginosa ATCC#15442 No Synergy

A: Surf. D B: Potassium Sorbate Media: 1/10 TSB Inoculum size: 1.808E+05PPM AI MIC Values (24 hrs) Test Alone Combination Ratio Organism CA CBCa Cb S.I. (Ca:Cb) S. aureus 20000 30000 5000 14991 0.75 1:2.9982 ATCC#20000 30000 1750 14991 0.59 1:8.5663 6538 20000 30000 1750 24011 0.891:13.7206 20000 30000 1750 18005 0.69 1:10.2886 20000 30000 875 240110.84 1:27.4411 20000 30000 875 18005 0.64 1:20.5771 20000 30000 87514991 0.54 1:17.1326 20000 30000 437.5 24011 0.82 1:54.8823 20000 30000437.5 18005 0.62 1:41.1543 20000 30000 437.5 14991 0.52 1:34.2651 2000030000 218.75 24011 0.81 1:109.7646 20000 30000 218.75 18005 0.611:82.3086 20000 30000 218.75 14991 0.51 1:68.5303

A: Surf. E B: Potassium Sorbate Media: PDB Inoculum size: 1.156E+06CFU/ml PPM AI MIC Values (3rd day) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) A. niger 20000 1000 5000 600 0.85 1:0.1200ATCC#16404 20000 1000 2500 800 0.93 1:0.3200

A: Surf. E B: Potassium Sorbate Media: PDB Inoculum size: 1.808E+06CFU/ml PPM AI MIC Values (48 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) C. albicans 20000 600 5000 300 0.75 1:0.0600ATCC#10203 20000 600 5000 400 0.92 1:0.0800 20000 600 2500 400 0.791:0.1600 20000 600 2500 500 0.96 1:0.2000 20000 600 1750 400 0.751:0.2286 20000 600 1750 500 0.92 1:0.2857 20000 600 875 500 0.881:0.5714

A: Surf. E B: Potassium Sorbate Media: 1/10TSB Inoculum size: 5.727E+07CFU/ml PPM AI MIC Values (24 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) Ps. aeruginosa 20000 14991 875 11995 0.841:13.7086 ATCC#15442 20000 14991 437.5 11995 0.82 1:27.4171

A: Surf. E B: Potassium Sorbate Media: 1/10TSB Inoculum size: 1.808E+06CFU/ml PPM AI MIC Values (24 hrs) Test Alone Combination Ratio OrganismCA CB Ca Cb S.I. (Ca:Cb) S. aureus 20000 30000 5000 11995 0.65 1:2.3990ATCC# 20000 30000 5000 14991 0.75 1:2.9982 6538 20000 30000 5000 180050.85 1:3.6010 20000 30000 2500 11995 0.52 1:4.7980 20000 30000 250014991 0.62 1:5.9964 20000 30000 2500 18005 0.73 1:7.2020 20000 300002500 24011 0.93 1:9.6044 20000 30000 1750 11995 0.49 1:6.8543 2000030000 1750 14991 0.59 1:8.5663 20000 30000 1750 18005 0.69 1:10.288620000 30000 1750 24011 0.89 1:13.7206 20000 30000 875 11995 0.441:13.7086 20000 30000 875 14991 0.54 1:17.1326 20000 30000 875 180050.64 1:20.5771 20000 30000 875 24011 0.84 1:27.4411 20000 30000 437.514991 0.52 1:34.2651 20000 30000 437.5 18005 0.62 1:41.1543 20000 30000437.5 24011 0.82 1:54.8823 20000 30000 218.75 14991 0.51 1:68.5303 2000030000 218.75 18005 0.61 1:82.3086 20000 30000 218.75 24011 0.811:109.7646

The following biocides had no synergy against any organism tested whenpaired with the following surfactants:

Surf. A

Sodium Benzoate, TRIS NITRO

Surf. E

DMDMH

Surf. D

CS-1246, OPP, DMDMH

In the following combinations, the ratio of surfactant to biocide wheresynergy was observed were not commercially relevant, i.e., a ratio of1:0.2 or greater (less biocide relative to surfactant). At these ratios,the biocide levels in a formulated product would be too low to bepractical:Surf. ADIDAC, IPBCSurf. ECMIT/MIT, IPBC, OIT, TTPC, WSCPSurf. DCMIT/MIT, OIT, DIDAC(MBIT, IPBC, WSCP were synergistic only at 1:0.05 or worse except forone data point)Stability Testing

A solution of sodium benzoate or potassium sorbate in water was made anddiluted with surfactant to give the desired ratios of biocide tosurfactant. Additional water was added as needed to give the indicate wt% solutions. The samples were split into three vials. One vial wasstored at room temperature, one was stored at 40° C. and one was storedat 50° C. Samples were evaluated after a week to determine stability.Samples that were cloudy or highly discolored were determined to beunstable. In the data tables, a dash indicates that the formulation wasstable.

Stability Data - 10% Sodium benzoate in combination with Surfactants -Day 1 Surfac- Temperature tant:Sodium Room Surfactant benzoateTemperature 40° C. 50° C. Surf. D 1:0.5 — — — 1:27 — — — 1:100 — — —Surf. E 1:27 — — — 1:10 — — — Surf. B 1:27 — — — POLYSOR- 1:10 — — —BATE 20 1:27 — — — 1:100 — — — Disodium 1:10 — — — cocoampho- 1:27 — — —diacetate 1:100 — — — TERGITOL 1:10 — — Cloudy L-62 1:27 — SlightlyCloudy cloudy 1:100 — Slightly Slightly cloudy cloudy TERGITOL 1:10Slightly Slightly Cloudy 81 cloudy cloudy 1:27 Slightly Slightly Cloudycloudy cloudy 1:100 — — Slightly cloudy TERGITOL 1:10 — — — 15-S-7 1:27— — — 1:100 — — — * Surf. B is R¹O(CH₂CH(CH₃)O)₅(CH₂CH₂O)₆H, where R¹ is2-ethylhexyl

Stability Data - 10% Sodium benzoate in combination with Surfactants -Day 2 Surfac- Temperature tant:Sodium Room Surfactant benzoateTemperature 40° C. 50° C. Surf. D 1:0.5 — — — 1:27 — — — 1:100 — — —Surf. E 1:27 — — — 1:10 — — — Surf. B 1:27 — — — POLYSOR- 1:10 — — —BATE 20 1:27 — — — 1:100 — — — Disodium 1:10 — — — cocoampho- 1:27 — — —diacetate 1:100 — — — TERGITOL 1:10 — — Cloudy L-62 1:27 — SlightlyCloudy cloudy 1:100 — Slightly Slightly cloudy cloudy TERGITOL 1:10Slightly Slightly Cloudy + 81 cloudy cloudy white precipitate 1:27Slightly Slightly Cloudy + cloudy cloudy white precipitate 1:100 — —Slightly cloudy + white precipitate TERGITOL 1:10 — — — 15-S-7 1:27 — —— 1:100 — — —

Stability Data - 10% Sodium benzoate in combination with Surfactants -Day 7 Surfac- Temperature tant:Sodium Room Surfactant benzoateTemperature 40° C. 50° C. Surf. D 1:0.5 — — — 1:27 — — — 1:100 — — —Surf. E 1:27 — — — 1:10 — — — Surf. B 1:27 — — — POLYSOR- 1:10 — — —BATE 20 1:27 — — — 1:100 — — — Disodium 1:10 — — — cocoampho- 1:27 — — —diacetate 1:100 — — — TERGITOL 1:10 — — Cloudy L-62 1:27 — SlightlyCloudy cloudy 1:100 — Slightly Slightly cloudy cloudy TERGITOL 1:10Slightly Cloudy Cloudy 81 cloudy 1:27 Slightly Cloudy Cloudy cloudy1:100 — Slightly Slightly cloudy cloudy TERGITOL 1:10 — — — 15-S-7 1:27— — — 1:100 — — —

Stability Data - 30% Sodium benzoate in combination with Surfactants -Day 1 Surfac- Temperature tant:Sodium Room Surfactant benzoateTemperature 40° C. 50° C. Surf. D 1:0.5 — — — 1:27 — — — 1:100 — — —Surf. E 1:27 — — — 1:10 — — — Surf. B 1:27 — — — POLYSOR- 1:10 — — —BATE 20 1:27 — — — 1:100 — — — Disodium 1:10 — — — cocoampho- 1:27 — — —diacetate 1:100 — — — TERGITOL 1:10 — — — L-61 1:27 — — — 1:100 — — —TERGITOL 1:10 — — — 81 1:27 — — — 1:100 — — — TERGITOL 1:10 — — — 15-S-71:27 — — — 1:100 — — —

Stability Data - 30% Sodium benzoate in combination with Surfactants -Day 2 Surfac- Temperature tant:Sodium Room Surfactant benzoateTemperature 40° C. 50° C. Surf. D 1:0.5 — — — 1:27 — — — 1:100 — — —Surf. E 1:27 — — — 1:10 — — — Surf. B 1:27 — — — POLYSOR- 1:10 — — —BATE 20 1:27 — — — 1:100 — — — Disodium 1:10 — — — cocoampho- 1:27 — — —diacetate 1:100 — — — Tergitol 1:10 — — — L-61 1:27 — — — 1:100 — — —TERGITOL 1:10 — — — 81 1:27 — — — 1:100 — — — TERGITOL 1:10 — — — 15-S-71:27 — — — 1:100 — — —

Stability Data - 30% Sodium benzoate in combination with Surfactants -Day 7 Surfac- Temperature tant:Sodium Room Surfactant benzoateTemperature 40° C. 50° C. Surf. D 1:0.5 — — — 1:27 — — — 1:100 — — —Surf. E 1:27 — — — 1:10 — — — Surf. B 1:27 — — — POLYSOR- 1:10 — — —BATE 20 1:27 — — — 1:100 — — — Disodium 1:10 — — — cocoampho- 1:27 — — —diacetate 1:100 — — — TERGITOL 1:10 — — White L-61 solid 1:27 — — —1:100 — — — TERGITOL 1:10 — — White 81 precipitate 1:27 — — — 1:100 — —— TERGITOL 1:10 — — — 15-S-7 1:27 — — — 1:100 — — —

Stability Data - 33% Potassium sorbate in combination with Surfactants -Day 3 Surfac- Temperature tant:Potassium Room Surfactant sorbateTemperature 40° C. 50° C. Surf. D 1:1 — — — 1:27 — — — 1:68 — — — 1:100— — — Surf. E 1:5 — — — 1:27 — — — 1:68 — — — 1:100 — — — Surf. A 1:0.5— — — 1:27 — — — Surf. B 1:0.5 — — — 1:27 — — — POLYSOR- 1:1 — — — BATE20 1:27 — — — 1:68 — — — 1:100 — — — Disodium 1:1 White White Whitecocoampho- precipitate precipitate precipitate diacetate 1:27 — — — 1:68— — — 1:100 — — — TERGITOL 1:1 — — — L-62 1:27 — — — 1:68 — — — 1:100 —— — TERGITOL 1:1 — — — 81 1:27 — Cloudy — 1:68 — Cloudy Cloudy 1:100 — —Cloudy TERGITOL 1:1 — — — 15-S-7 1:27 — — — 1:68 — — — 1:100 — — — Note:All Room Temperature and 40° C. samples were a light yellow color unlessnoted, and all 50° C. samples were dark yellow unless noted.

Stability Data - 33% Potassium sorbate in combination with Surfactants -Day 7 Surfac- Temperature tant:Potassium Room Surfactant sorbateTemperature 40° C. 50° C. Surf. D 1:1 — — Brown solid 1:27 — — — 1:68 —— — 1:100 — — — Surf. E 1:5 — — — 1:27 — — — 1:68 — — — 1:100 — — —Surf. A 1:0.5 — — — 1:27 — — — Surf. B 1:0.5 — — — 1:27 — — — POLYSOR-1:1 — Amber — BATE 20 1:27 — — — 1:68 — — — 1:100 — — — Disodium 1:1White White Brown cocoampho- precipitate precipitate solid diacetate1:27 — Amber — 1:68 — Amber — 1:100 — Amber — TERGITOL 1:1 — — BrownL-62 solid 1:27 — — — 1:68 — — — 1:100 — — — Tergitol 1:1 — — Brownsolid 81 1:27 — cloudy — 1:68 — — — 1:100 — — — Tergitol 1:1 — — —15-S-7 1:27 — — — 1:68 — — — 1:100 — — — Note: All Room Temperature werea light yellow color unless noted, all 40° C. samples were dark yellowunless noted, and all 50° C. samples were amber unless noted.

The invention claimed is:
 1. A synergistic microbicidal compositioncomprising: (a) a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅H where R² is a mixture of C₈-C₁₄ linearalkyl groups; and (b) a benzoate or sorbate salt; wherein a weight ratioof said nonionic surfactant to the benzoate or sorbate salt is from1:0.12 to 1:109.7646; and wherein said mixture of C₈-C₁₄ linear alkylgroups comprises from 60 to 75 wt % C₈-C₁₀ linear alkyl groups and 25 to40 wt % C₁₂-C₁₄ linear alkyl groups.
 2. A method for inhibiting thegrowth of microorganisms in an aqueous medium; said method comprisingadding to said aqueous medium: (a) a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₅H where R² is a mixture of C₈-C₁₄ linearalkyl groups; and (b) a benzoate or sorbate salt; wherein a weight ratioof said nonionic surfactant to the benzoate or sorbate salt is from1:0.12 to 1:109.7646; and wherein said mixture of C₈-C₁₄ linear alkylgroups comprises from 60 to 75 wt % C₈-C₁₀ linear alkyl groups and 25 to40 wt % C₁₂-C₁₄ linear alkyl groups.
 3. A synergistic microbicidalcomposition comprising: (a) a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇H where R² is a mixture of C₈-C₁₄ linearalkyl groups; and (b) a benzoate or sorbate salt; wherein a weight ratioof said nonionic surfactant to the benzoate salt is from 1:3.6010 to1:109.7646 and a ratio of said nonionic surfactant to the sorbate saltis from 1:0.06 to 1:0.5714 or 1:2.3990 to 1:109.7646; and wherein saidmixture of C₈-C₁₄ linear alkyl groups comprises from 60 to 75 wt %C₈-C₁₀ linear alkyl groups and 25 to 40 wt % C₁₂-C₁₄ linear alkylgroups.
 4. A method for inhibiting the growth of microorganisms in anaqueous medium; said method comprising adding to said aqueous medium:(a) a nonionic surfactant with structure:R²O(CH₂CH(CH₃)O)₃(CH₂CH₂O)₇H where R² is a mixture of C₈-C₁₄ linearalkyl groups; and (b) a benzoate or sorbate salt; wherein a weight ratioof said nonionic surfactant to the benzoate salt is from 1:3.6010 to1:109.7646 and a ratio of said nonionic surfactant to the sorbate saltis from 1:0.06 to 1:0.5714 or 1:2.3990 to 1:109.7646; and wherein saidmixture of C₈-C₁₄ linear alkyl groups comprises from 60 to 75 wt %C₈-C₁₀ linear alkyl groups and 25 to 40 wt % C₁₂-C₁₄ linear alkylgroups.